DUBAI, Dec 29 (Reuters) – An influential cleric of Saudi Arabia’s hardline Sunni school of Islam has denounced Shi’ite Muslims as “infidels” in a new religious edict that comes amid rising sectarian tension in the region.

“The rejectionists (Shi’ites) in their entirety are the worst of the Islamic nation’s sects. They bear all the characteristics of infidels,” Sheikh Abdel-Rahman al-Barrak said in the fatwa, or ruling, distributed on Islamist Web sites.

“They are in truth polytheist infidels, though they hide this,” it said, citing theological differences 14 centuries after the death of the Prophet Mohammad, such as reverence of shrines which followers of Saudi Arabia’s Wahhabi school consider abhorrent.

Concern is growing in Saudi Arabia, birthplace of Islam, over Shi’ite-Sunni violence in Iraq which has taken the northern neighbour to the brink of civil war. Sunni-Shi’ite tensions are also high in Lebanon, where Shi’ites are leading efforts to bring down a Sunni-led cabinet.

“The Sunni and Shi’ites schools of Islam are opposites that can never agree, there can be no coming together unless Sunnis give up their principles,” the fatwa said.

Barrak, an independent scholar, has come to be regarded by many as the highest authority for Wahhabi Muslims.

Clerics of the austere Wahhabi school of Sunni Islam have long dismissed Shi’ites as virtual heretics and Saudi Arabia’s Shi’ite minority complains of second class treatment.But Barrak’s fatwa was the strongest in recent years.

The fatwa, which was published on Barrak’s Web site in response to a follower’s question, also appeared to criticise efforts by some government-backed Saudi preachers at reconciliation between Sunnis and Shi’ites.

Saudi Arabia fears that violence between Sunnis and Shi’ites could lead to the break-up of Iraq and spill over its borders.

Barrak was among 38 clerics who issued a statement this month calling on world Sunnis to support their brethren in Iraq.